There has been known a noninvasive living body measurement apparatus that measures blood components by imaging a living body with the use of an imaging means to analyze a blood vessel in a living body image. The techniques as described above include a noninvasive living body measurement apparatus as disclosed in U.S. Patent Application Publication No. 2004-162471.
According to this noninvasive living body measurement apparatus, a wrist including a blood vessel (vein) is irradiated by a light source to measure blood components based on the image obtained by imaging the irradiated wrist, thereby displaying the measurement result on a display section. In order to image the to-be-measured blood vessel appropriately, the to-be-measured blood vessel must be positioned at a region suitable for the imaging by an imaging section. Thus, the noninvasive living body measurement apparatus disclosed in the above publication generates a blood vessel image showing the to-be-measured blood vessel based on the living body image obtained from the imaging section to display the image on the display section and displays, on the display section, an index showing the region suitable for the imaging by the imaging section, so that the positioning can be performed easily.
By the way, among blood vessels existing in an arm, blood vessels existing in a wrist are particularly suitable for an imaging. The reason is that wrist veins exist at such shallow positions from the skin that allows visual recognization of the veins, the positions cause smaller light scattering in the living body, and the blood vessels have a thick and simple shape, thus allowing the blood vessels to be imaged clearly. The noninvasive living body measurement apparatus disclosed in the publication is configured so that the imaging section is provided just above a wristband. This configuration requires the wristband to be wound around the wrist in order to image the blood vessels existing in the wrist. However, since the wrist includes joints as a movable section, it has been difficult to wear a wristband having an imaging section and having a width.